U.S. patent application number 14/356575 was filed with the patent office on 2014-10-23 for disk brake, and pressure plate and brake pad for such a disk brake.
The applicant listed for this patent is WABCO Radbremsen GmbH. Invention is credited to Hellmut Jager.
Application Number | 20140311836 14/356575 |
Document ID | / |
Family ID | 47221292 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140311836 |
Kind Code |
A1 |
Jager; Hellmut |
October 23, 2014 |
DISK BRAKE, AND PRESSURE PLATE AND BRAKE PAD FOR SUCH A DISK
BRAKE
Abstract
The invention relates to a disk brake, in particular for
commercial vehicles, comprising a brake pad, a brake application
device for pressing the brake pad against a brake disk, a pressure
plate, by way of which the brake application device presses the
brake pad against the brake disk during the braking process, and
comprising an inclined guide, which during braking guides the
pressure plate along a path located transversely to the brake axis.
The pressure plate is provided with a protrusion, and the brake pad
is provided with a recess, which accommodates the protrusion when
assembled.
Inventors: |
Jager; Hellmut;
(Ludwigshafen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WABCO Radbremsen GmbH |
Mannheim |
|
DE |
|
|
Family ID: |
47221292 |
Appl. No.: |
14/356575 |
Filed: |
November 8, 2012 |
PCT Filed: |
November 8, 2012 |
PCT NO: |
PCT/EP2012/004651 |
371 Date: |
May 6, 2014 |
Current U.S.
Class: |
188/73.1 |
Current CPC
Class: |
F16D 65/0971 20130101;
F16D 2055/0008 20130101; F16D 2065/026 20130101; F16D 65/095
20130101; F16D 2055/0016 20130101; F16D 55/226 20130101; F16D
65/092 20130101 |
Class at
Publication: |
188/73.1 |
International
Class: |
F16D 65/097 20060101
F16D065/097; F16D 65/092 20060101 F16D065/092 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2011 |
DE |
10 2011 118 313.6 |
Claims
1. A disk brake, especially for commercial vehicles, comprising: a
brake pad, a brake application device for pressing the brake pad
against a brake disk, a pressure plate by way of which the brake
application device presses the brake pad against the brake disk
during a braking process, and an inclined guide which guides the
pressure plate along a path lying obliquely to a brake axis during
the braking process, characterized by a projection on the pressure
plate and a recess in the brake pad which accommodates the
projection in an assembled state.
2. The disk brake according to claim 1, characterized by a play
present between a side boundary of the projection and a
corresponding interior boundary of the recess.
3. The disk brake according to claim 1, characterized in that a
depth of the recess corresponds at least to a thickness of a back
plate (48) of the brake pad.
4. The disk brake according to claim 1, characterized in that the
projection lies in a radially inward region of the pressure plate
and/or the recess lies in a radially inward region of the brake
pad.
5. The disk brake according to claim 1, characterized in that the
projection is made as a single piece with the pressure plate.
6. The disk brake according to claim 1, characterized in that the
pressure plate is a separate part.
7. A pressure plate for a disk brake according to claim 1.
8. A brake pad for a disk brake according to claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a 35 U.S.C. .sctn.371 national
phase entry application of, and claims priority to, International
Patent Application No. PCT/EP2012/004651, filed Nov. 8, 2012, which
claims priority to German Patent Application No. DE 10 2011 118
313.6, filed Nov. 11, 2011, the disclosures of which are hereby
incorporated by reference in their entirety for all purposes.
BACKGROUND
[0002] The invention concerns a disk brake, especially for
commercial vehicles, with a brake pad, a brake application device
for pressing the brake pad against a brake disk, a pressure plate
by way of which the brake application device presses the brake pad
against the brake disk during the braking process, and an inclined
guide which guides the pressure plate along a path lying obliquely
to the brake axis during the braking process.
[0003] Disk brakes of the aforementioned kind are known, for
example, from EP 1 637 759 A1.
[0004] Such brakes can be activated pneumatically and/or
electromechanically, for example. In this case, by means of a
relatively small attack surface of the brake application device
arranged in the brake caliper, a large force component is applied
by at least one pressing spindle mechanism perpendicular to the
plane of the brake disk against a large-surface brake pad,
consisting of a pad support plate (back plate) and a friction
lining attached thereto and contacting the brake disk in the
braking process. In what follows, the invention is explained more
closely by means of preferred sample embodiments making reference
to the enclosed drawing with further details.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1, a schematic top view of a disk brake according to
one sample embodiment of the invention,
[0006] FIG. 2, a sectional view along line II-II of FIG. 1,
[0007] FIG. 3, a partial view of the brake of FIG. 1 at the
application side,
[0008] FIG. 4, the pressure plate of the brake of FIG. 1 and its
guidance in the brake part,
[0009] FIG. 5, an enlarged view of the part of the brake of FIG. 2
designated as "V",
[0010] FIG. 6, a sectional view along line VI-VI of FIG. 5,
[0011] FIG. 7, schematically, a pressure plate according to another
sample embodiment of the invention,
[0012] FIG. 8, the pressure plate of FIG. 7 with the corresponding
brake pad situated in front of it, and
[0013] FIG. 9, the same view as FIG. 2, but with the pressure plate
and the brake pad according to FIGS. 7 and 8.
DETAILED DESCRIPTION
[0014] For reasons of economy (such as weight, material) and the
narrow space available (for installation), the back plate is not
excessively thick and rigid. In the brake according to the
invention, a pressure plate or pressure distributing plate is used
between the brake application device and the back plate. This
pressure plate is appropriately rigid so that its contact surface,
extending over approximately the surface of the back plate, ensures
that the brake pad is pressed against the brake disk as uniformly
as possible and free of deformation.
[0015] The invention pertains in particular to brakes in which both
the brake pad and the pressure plate constitute separate parts and
are installed in or removed from the brake radially through a brake
caliper opening. This is done during new installation, during
servicing as part of a brake inspection, and when replacing the
pressure plate and/or brake pad. The pressure plate here is not
wider than the brake pad.
[0016] The two aforementioned parts of brake pad and pressure plate
are guided for example at the application side in a fixed brake
support and/or in shaft openings in the brake caliper laterally
and/or radially inward on the broadest possible contact surfaces
and braced by these surfaces. The brake pad can be bounded in both
directions by bracing horns.
[0017] The brake pad is often guided radially on contact surfaces
situated on shoulders or on a connection yoke between the bracing
horns. On the other hand, it is possible according to the invention
to guide the pressure plate only radially on these contact
surfaces, while in addition it engages by a lower lying shoulder
(to prevent twisting) with a groove of the brake support or the
brake caliper, producing a forced guidance. Thus, in this
configuration, the pressure plate is "hanging". On the whole, there
is a basically U-shaped shaft.
[0018] To accomplish the oblique guidance of the pressure plate,
the aforementioned groove lies increasingly closer in the preferred
direction of rotation of the brake disk in forward travel in the
contact surface on the brake disk run-in side, and in addition the
groove is inclined at an angle relative to the disk run-in. Thus,
there is an oblique groove which serves to guide the pressure
plate. The size of the respective angle depends on the installation
situation.
[0019] Thus, during the braking process, an opposite relative
movement of the application-side brake pad on the one hand and the
pressure plate on the other. This serves to stabilize and even out
the wear on the pad. The invention is especially applicable to disk
brakes in which the brake pads and the pressure pads are clamped in
the required position by means of hold-down springs and a hold-down
element to prevent rattling noises and dropping out of the
brake.
[0020] After a certain size of disk brake, especially in the case
of commercial vehicle disk brakes, it is necessary to use brake
pads of different quality or different dimensions according to the
situation. This then also applies to the pressure plate.
[0021] Due to these different designs, mistakes cannot be ruled
out, both in regard to the matching of parts and their
installation. Thus, it can happen that brake pads with slightly
different dimensions are installed during a servicing job in regard
to the existing brake pad shafts, or installation items or
installation sides are mixed up. There are also known cases where
servicing intervals were not obeyed and then after falling below
the permissible residual thickness of the brake disk or pad the
brake pad was torn off into the free space between the brake disk
and the shaft guide.
[0022] The problem of the invention is to modify the disk brakes of
the above mentioned kind in terms of economy so that the operating
and functional reliability and the servicing friendliness are
improved with little design cost.
[0023] According to the invention, the problem is solved by a
projection on the pressure plate and a recess in the brake pad
which accommodates the projection in the assembled state.
[0024] In other words, the brake lining has a recess or cavity in
which the projection of the pressure plate is inserted. This
provides a coding of parts. It is based in particular on the
pressure plate. Thus, the pressure plate only matches up with the
corresponding brake pad.
[0025] According to the invention, a play is preferably present
between a side boundary of the projection and the corresponding
interior boundary of the recess. This ensures a relative
displacement of the brake pad on the one hand and that of the
pressure plate on the other hand with respect to each other in the
direction parallel to the plane of the disk brake. In particular,
on account of the oblique guidance of the pressure plate over the
entire wearing distance of pad and disk, the width of the recess is
sufficiently large to avoid any "contact collision" over the entire
wearing distance. In other words, there is a lateral functional
play in the recess.
[0026] According to one preferred embodiment of the invention, the
depth of the recess corresponds at least to the thickness of a back
plate of the brake pad. If the brake pad is further displaced on
account of falling below the permissible residual thickness of
brake pad/disk brake, it will continue to engage the projection and
"hang", depending on the position of the disk and its direction of
turning, so that it cannot be torn off into the free space between
brake disk and shaft guidance.
[0027] According to another preferred embodiment of the invention,
the projection lies in the radially inward region of the pressure
plate and/or the recess lies in the radially inward region of the
brake pad.
[0028] Because the brake pad is directly radially installed for
example when the pressure plate has been installed and the
projection does not need to be surrounded by the recess on all
sides, no axial movements of the brake pad relative to the pressure
plate are required to bring the two parts into contact against each
other. This holds not only during installation, but also during
removal.
[0029] Furthermore, with this configuration, only a negligible
portion of the frictional surface is lost due to the recess.
Furthermore, the projection and the recess lie in an approximately
"force-neutral" region. If, instead, the projection or the recess
was situated approximately in the middle region of the pressure
plate or the brake pad, it would be at the center of the force
application, for example, where a pressing spindle applies the
braking force. This might result in material stresses and/or
material cracks. Furthermore, the above-mentioned drawback of a
form fitting would exist, making an installation difficult.
[0030] Again preferably, the projection according to the invention
is made as a single piece with the pressure plate. This reduces the
number of parts. Moreover, the installation and removal is
especially easy.
[0031] Finally, it is especially preferable according to the
invention that the pressure plate is a separate part.
[0032] Because the coding is based on the pressure plate and the
brake pad, no additional work or special matching to the brake
caliper and/or brake support is required. This is a substantial
contribution to the economy.
[0033] It is expressly pointed out that the coding system of the
invention does not require a recess in the form of a continuous
opening. Instead, the recess can also have the form of a blind
hole. Neither does it need to be bounded on all sides by side
walls. Instead, the side walls can also form a U.
[0034] Besides the disk brake specified above, the invention also
creates a pressure plate and a brake pad for such a disk brake.
[0035] The disk brake shown in the drawing according to one sample
embodiment of the invention includes a caliper 10, which is a
sliding caliper and which has a radial opening 12, a brake support
14, a brake pad 16 at the rim side, a brake pad 18 at the
application side, a pressure plate 20, hold-down springs 22, 24, 26
for the brake pads 16 and 18 and for the pressure plate 20,
respectively, and a hold-down stirrup 28 for the hold-down springs
22, 24, and 26.
[0036] Inside the lower part of the brake caliper 10 shown in FIG.
1 is a brake application device, not shown here. In the braking
process, this presses against the pressure plate 20, which in turn
presses the brake pad 18 against a disk brake, not shown in the
drawing. The plane B of the disk brake is shown by broken line. The
force of the reaction which occurs moves the brake caliper 10
downward in FIG. 1, which also presses the brake pad 16 against the
brake disk. The brake application device also includes a pressing
spindle mechanism, also not shown in the drawing, by means of which
the brake can be adjusted to compensate for wear. The preferred
direction of rotation of the brake disk when driving forward is
indicated by the arrow D.
[0037] The brake pads 16, 28 and the pressure plate 20 are guided
and/or braced in shaft guides of the brake caliper 10 and/or the
brake support 14. These can be installed or removed through the
opening 12.
[0038] FIG. 2 shows the brake pad 18 at the application side with
the pressure plate 20 behind it (broken line), both of them lying
within an essentially U-shaped shaft guide.
[0039] FIG. 3 shows a brake part with the guides for the pressure
plate 20 and the brake pad in front of it from the application
side. The brake pad 18 is wider than the pressure plate 20.
[0040] The shaft guides include braces 30, 32 acting in the
circumferential direction and braces 34, 36 acting in the radial
direction, both in terms of the brake axis A.
[0041] Radially on the inside the pressure plate 20 has a guide
projection 38, which is guided in a guide slot 40 in the brake
support 24. The guide slot 40 is tilted by an angle .alpha.
relative to the brake axis A, so that it runs at a slant. Thus,
there is an oblique guide for the pressure plate 20. The angle
.alpha. should be chosen in consideration of the other
circumstances. The oblique guide has substantial benefits. In this
context, refer to EP 1 637 759 A1.
[0042] In the corners shown at lower right and lower left in FIG.
2, the brake pad 18 has a recess 42, 44. The recess 44 in the
assembled state engages with a projection 46 formed on the pressure
plate 20. As is especially evident in the sectional view of FIG. 6,
the projection 46 is hook shaped in the sample embodiment depicted.
As is also evident from the sectional representation of FIG. 6, the
recess 44 is formed both on the back plate 48 and on the friction
lining 50 of the brake pad 18, so that its depth is the same as or
slightly greater than the thickness of the back plate 48. As a
result, the hook-shaped projection 46 can still secure the brake
pad 18 when the friction lining 50 is largely worn away. Of course,
the length by which the hook-shaped projection 46 protrudes into
the recess 44 must also be sufficient in this respect. This
configuration according to the invention has the benefit that the
hook-shaped projection sticking out from the pressure plate
protrudes into the recess or cavity of the back plate, which does
not lie in the region of the immediate contact surface of the
pressure plate against the back plate, so that no pressure
transmitting region of the pressure plate surface is lost.
Furthermore, no material stresses can be created. This also holds,
of course, for more than one projection or more than one recess in
all the embodiments.
[0043] As is especially evident in FIGS. 2 and 5, the projection 46
engages in the recess 44 with a lateral play. This play is
necessary in view of the fact that, because of the oblique guidance
38, 40, the pressure plate 20 moves parallel to the brake disk in
regard to the brake pad 18, when the pressure plate 20 is moving
together with the brake pad 18 in the direction of the brake disk
during the braking process.
[0044] In the sample embodiment of FIGS. 1 to 6, the brake pad 18
is provided with two recesses 42, 44, while the pressure plate 40
has one projection 46. But the invention is not limited to this
embodiment. Instead, a second projection can also be provided on
the pressure plate 20, which for example engages with the recess
42. Several recesses and several projections can also be provided.
The aforementioned coding can accordingly be realized by variation
of the shapes, the number, and/or the positioning of the recesses
and/or the projections.
[0045] Another sample embodiment is shown in FIGS. 7 to 9. Here,
the pressure plate 20 has a central projection 52, which engages
with a recess 54 on the brake pad 18. As is especially evident in
FIGS. 8 and 9, the projection 52 is accommodated in the recess 54
with play on both sides, in order to account for the relative
movement of the oblique guide 38, 40.
[0046] The features of the invention disclosed in the above
specification, the claims, and the drawing can be essential to the
realization of the invention in its various embodiments, both
individually and in any given combinations. Neither is the
invention limited merely to the sliding caliper disk brake
described in the sample embodiment, but also for other caliper
designs, such as fixed or pendulum caliper disk brakes.
* * * * *